Dog Nutrition and Food Supplements: What You Need to Know

Dog Nutrition and Food Supplements: What You Need to Know

How much should you feed your dog? Does the food you are providing meet your dog’s nutritional needs? As our knowledge of the relationship between diet and health continues to expand and as the range of foods available for dogs continues to grow, it is now more important than ever to base our feeding choices on good information.

The information in this article is based on Nutrient Requirements of Dogs and Cats, a technical report issued by the National Research Council as part of its Animal Nutrition Series. The Food and Drug Administration relies on information in that report to regulate and ensure the safety of pet foods.

Essential Dog Nutrients

Dogs need certain essential nutrients to survive: amino acids from proteins, fatty acids and carbohydrates, vitamins, minerals and water. Below you will find the recommended daily allowances for dietary nutrients based on the minimum amount required to maintain good health in normal dogs.

Your dog’s unique nutritional requirements depend on its size, breed and stage in life, among other factors. A better understanding of how dogs use the various nutrients in food and how much of them they need will help you choose a healthier diet for your pet.

Proteins and Amino Acids

Dogs cannot survive without protein in their diets. Dietary protein contains 10 specific amino acids that dogs cannot make on their own. Known as essential amino acids, they provide the building blocks for many important biologically active compounds and proteins. Additionally, they donate the carbon chains needed to make glucose for energy.

High-quality proteins have a good balance of all of the essential amino acids. Studies show that dogs can tell when their food lacks a single amino acid and will avoid such a meal.

Dogs are known to selectively choose foods that are high in protein. Whether this is simply a matter of taste or a complex response to their biological needs for all 10 essential amino acids is at present unknown. However, dogs can survive on a vegetarian diet, as long as it contains sufficient protein and is supplemented with vitamin D.

Fats and Fatty Acids

Dietary fats, mainly derived from animal fats and the seed oils of various plants, provide the most concentrated source of energy in the diet. They supply essential fatty acids that cannot be synthesized in the body and serve as carriers for important fat-soluble vitamins.

Fatty acids play a role in cell structure and function. Food fats tend to enhance the taste and texture of the dog’s food as well. Essential fatty acids are necessary to keep your dog’s skin and coat healthy. Puppies fed ultralow-fat diets develop dry, coarse hair and skin lesions that become increasingly vulnerable to infections.

Deficiencies in the Omega-3 family of essential fatty acids may be associated with vision problems and impaired learning ability. Another family of essential fatty acids called Omega-6 has been shown to have important physiologic effects in the body.

Daily Recommended Allowances for Protein and Fats
Puppies (Weighing 12 lb – 33 lb at maturity) Adult Dogs (Weighing 33 lb) Pregnant / Nursing Dogs (Weighing 33 lb with 6 puppies)
Crude* Protein 56 g 25 g 69 g / 158 g
Total Fat 21 g 14 g 29 g / 67 g

*”Crude” refers to the specific method of testing the product, not to the quality of the nutrient itself.

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Determining Grams of Essential Nutrients from Petfood Labels

Pet food labels do not always list amounts of essential nutrients in grams. However, all pet food labels must state guarantees for the minimum percentages of crude protein and crude fat, and the maximum percentages of crude fiber and moisture. To convert these percentages to grams, simply multiply the crude percentages times the weight of your dog’s daily portion.

For example, if you feed your dog a 1-lb (454-gram) can of food per day, and the food contains 8% crude protein, the grams of protein would be 0.08 x 454 = 36 grams.

Energy Needs

Dogs need a certain amount of energy to sustain the normal activities of their daily lives. Growth, pregnancy, lactation and exercise all increase these normal energy requirements. Generally measured in terms of calories, energy comes from three major dietary components: carbohydrates, protein, and fats.

Omnivorous animals get some of their energy from carbohydrates, which include sugars, starches and dietary fibers. The major sources of carbohydrates in commercial
dog foods are cereals, legumes, and other plant foodstuffs. So-called absorbable carbohydrates, including glucose and fructose, can be directly absorbed and do not need to be digested by enzymes.

Digestible carbohydrates are readily broken down by intestinal tract enzymes. Fermentable carbohydrates include certain starches and dietary fibers that pass ndigested through the small intestine to the colon, where they are fermented by microbes into short-chain fatty acids and gases. Some studies suggest that fermentable fibers may aid in the regulation of blood glucose concentrations and enhance immune function. Non-fermentable fibers, such as cellulose and wheat bran, contribute little in terms of energy or nutrition and are primarily used to decrease caloric intake of the overweight animal.

Average Daily Energy Needs
Calories per Day (Kilocalories per Day)
Type of Dog 10 lb 30 lb 50 lb 70 lb 90 lb
Puppies (10 lb puppy growing to 33 lb at maturity) 990
Inactive dogs (dogs with little stimulus or opportunity to exercise) 296 674 989 1,272 1,540
Adult active dogs (dogs with strong stimulus and ample opportunity to exercise, such as dogs in households with more than one dog, in the country or with a large yard) 404 922 1,353 1,740 2,100
Pregnant dogs (from 4 weeks after mating until delivery) 518 1,274 1,940 2,570 3,170
Young adult active dogs 436 993 1,451 1,876 2,264
Older active dogs 327 745 1,093 1,407 1,700


  Energy Needs in Calories

(Calories per Day for a 33 lb and 50 lb Nursing Dog)

Number of Puppies Weeks into Lactation
1 2 3 (peak) 4
33 lb 50 lb 33 lb 50 lb 33 lb 50 lb 33 lb 50 lb
2 1,645 2,328 1,789 2,546 1,897 2,709 1,969 2,818
4 2,185 3,146 2,473 3,581 2,689 3,909 2,833 4,127
6 2,455 3,555 2,815 4,100 3,084 4,509 3,265 4,782
8 2,725 3,964 3,157 4,618 3,481 5,109 3,697 5,437
Energy Needs of Growing Puppies

The growing puppy starts out needing about twice as many calories per pound of body weight as an adult dog of the same breed. Owners should start feeding puppies food at approximately 4 weeks after birth, because mother’s milk is no longer sufficient. Food is best offered to puppies in multiple, well-spaced meals.

Energy Needs of Older Dogs

Because of decreased physical activity and slowed metabolism, older dogs need 20% fewer total calories than do middle-aged adult dogs. As dogs age, they tend to become overweight. It may take obese dogs longer for their blood glucose concentrations to return to normal. This disrupted carbohydrate metabolism can lead to diabetes.

Energy Needs of Lactating Dogs

New mothers generally suckle their puppies for at least 6 weeks. The mother’s need for calories increase with the number of puppies and the week of lactation, up to 4 weeks. Giant breeds (like Great Danes) have proportionately smaller digestive tracts and may not be able to eat enough to sustain themselves during lactation. Owners of such dogs may need to start feeding puppies supplemental food at an early age.

Vitamin K Activation of clotting factors, bone proteins, and other proteins 0.41 mg No reports of naturally occurring deficiencies in normal dogs
Vitamin B1 (Thiamin) Energy and carbohydrate metabolism; activation of ion channels in neural tissue 0.56 mg Failure to grow, weight loss and neurological abnormalities in puppies; damage to the nervous system and to the heart in adult dogs
Riboflavin Enzyme functions 1.3 mg Anorexia; weight loss; muscular weakness; flaking dermatitis; eye lesions
Vitamin B6 Glucose generation; red blood cell function; niacin synthesis; nervous system function; immune response; hormone regulation; gene activation 0.4 mg Anorexia and weight loss in puppies; convulsions, muscle twitching and anemia in adult dogs; impairment of motor control and balance; muscle weakness
Niacin Enzyme functions 4 mg Anorexia; weight loss; inflammation of the lips, cheeks, and throat; profuse salivation; bloody diarrhea; bloody feces; convulsions
Pantothenic Acid Energy metabolism 4 mg Erratic food intake; sudden prostration or coma; rapid respiratory and heart rates; convulsions; gastrointestinal symptoms; reduced antibody production
Vitamin 12 Enzyme functions 9 μg Appetite loss; lack of white blood cells; anemia; bone marrow changes
Folic Acid Amino acid and nucleotide metabolism; mitochondrial protein synthesis 68 μg Weight loss; decline in hemoglobin concentration
Choline Phospholipid cell membrane component 425 mg Loss of body weight; fatty liver

*Daily needs for an adult dog weighing 33 pounds, consuming 1,000 Calories per day. g = grams; mg = milligrams; μg = micrograms

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Twelve minerals in the table are known to be essential nutrients for dogs. Calcium and phosphorus are crucial to strong bones and teeth. Dogs need magnesium, potassium and sodium for nerve impulse transmission, muscle contraction, and cell signaling. Many minerals that are present only in minute amounts in the body, including selenium, copper and molybdenum, act as helpers in a wide variety of enzymatic reactions.

Dogs can get too much or too little of a specific mineral in their diets. A deficiency of dietary calcium, for instance, causes a condition known as secondary hyperparathyroidism. Recognized clinically for many years in dogs fed meals consisting mainly of meat, this disease results in major bone loss, skeletal abnormalities and pathological fractures. An excess of calcium, on the other hand, may also cause skeletal abnormalities, especially in growing large-breed puppies.

Daily Recommended Allowances for Minerals
Functions Daily Recommended Allowance* Signs of Deficiency / Excess
Calcium Formation of bones and teeth; blood coagulation; nerve impulse transmission; muscle contraction; cell signaling 1 g Nutritional secondary hyperparathyroidism; significant decreases in bone mineral content, which can result in major skeletal abnormalities; different types of skeletal aberrations, especially in growing puppies of large breeds
Phosphorus Skeletal structure; DNA and RNA structure; energy metabolism; locomotion; acid-base balance 0.75 g Reduced weight gain; poor appetite; bowing and swelling of forelimbs in puppies
Magnesium Enzyme functions; muscle and nerve-cell membrane stability; hormone secretion and function; mineral structure of bones and teeth 150 mg Reduction in weight gain, irritability, and convulsions in puppies; hyperextension of carpal joints and hind-leg paralysis later in life
Sodium Acid-base balance; regulation of osmotic pressure; nerve impulse generation and transmission 200 mg Restlessness; increased heart rate, water intake and hemoglobin concentration; dry and tacky mucous membranes
Potassium Acid-base balance; nerve-impulse transmission; enzymatic reactions; transport functions 1 g Poor growth in puppies; paralysis of neck muscles and rear legs and general weakness later in life
Chlorine Acid-base balance; transfer of extracellular fluids across cell membranes 300 mg Reduced weight gain and weakness in puppies
Iron Synthesis of blood components; energy metabolism 7.5 mg Poor growth; pale mucous membranes; lethargy; weakness; diarrhea; at acute levels, dangerous oxidative reactions that lead to gastrointestinal and other tissue damage
Copper Connective tissue formation; iron metabolism; blood cell formation; melanin pigment formation; myelin formation; defense against oxidative damage 1.5 mg Loss of hair pigmentation in puppies; anemia
Zinc Enzyme reactions; cell replication; protein and carbohydrate metabolism; skin function; wound healing 15 mg Poor weight gain; vomiting; skin lesions
Manganese Enzyme functions; bone development; neurological function 1.2 mg No studies of deficiency in dogs
Selenium Defense against oxidative damage; immune response 90 μg Anorexia; depression; breathing discomfort; coma; muscular degeneration
Iodine Thyroid hormone synthesis; cell differentiation; growth and development of puppies; regulation of metabolic rate 220 μg Enlargement of thyroid glands; dry, sparse hair coat; weight gain; excessive tearing, salivation and nasal discharge; dandruff

*Daily needs for an adult dog weighing 33 pounds, consuming 1,000 calories per day. g = grams; mg = milligrams; μg = micrograms

Feeding Practices

Should Your Dog Eat Meat?

As dogs are descended from omnivores, they are not strict meat eaters. They are remarkably adaptable to a wide range of ingredients, texture and form in terms of what they will eat. Though many dogs may prefer animal-based protein, they can thrive on a vegetarian diet.

Regardless of whether the protein comes from plant or animal sources, normal adult dogs should get at least 10% of their total calories from protein. Older dogs appear to require somewhat more protein to maintain their protein reserves, perhaps as much as 50% more.

How Much Fiber Is Good for Your Dog?

Fiber in the diet is probably good for overall gastrointestinal health and may help some dogs keep their weight down. Typical diet of normal adult dogs contains between 2.5 and 4.5% fiber. However, the fiber content of some “diet” dog foods may be higher. This may allow the dog to feel full without consuming too many calories for effective weight control. Diets high in fiber also may help in the management of hyperglycemia (high blood sugar) and may improve large intestine function.

On the other hand, too much fiber in the diet can decrease the digestibility of other important nutrients and result in loose stools, frequent defecation and reduced palatability of the dog food. Wheat bran and barley products are high in fiber. Conversely, dog food ingredients high in starch, including rice and dried potatoes, have less fiber.

How Often Should You Feed Your Dog?

Dogs eat larger, less frequent meals than do cats. It is fine to feed an adult dog one or two times per day. Puppies, however, need two to three daily meals.

How Can You Help Your Overweight Dog Trim Down?

The most obvious answer is to feed your dog smaller amounts on the same feeding schedule. Some dog owners offer less tasty food or allow less time to eat. Another option is to feed your dog one of the low-calorie dog foods on the market. It’s also important to remember to refrain from giving your dog table scraps.

How Do Heat and Exercise Affect the Amount of Water Your Dog Needs?

Fresh water should be available to your dog at all times to reduce the risk of becoming overheated. A dog’s need for water increases in keeping with the amount of energy he or she expends during exercise and this need may more than double in warm conditions. Ideally, you should actively offer your dog water during exercise.

Food Choices

Commercial dog foods come in a variety of forms. The most common types are dry, semimoist and canned. The moisture content of these foods ranges from 6% to 10% for dry, 15% to 30% for semimoist and 75% for canned. Most canned food has relatively more fat and protein and fewer carbohydrates than does dry and semimoist food and generally contains much higher levels of animal products.

Pet food labels must list the percentage of protein, fat, fiber and water in the food. When reading labels, it is important to remember that what may appear to be a big difference in the amount of a nutrient (for example, 8% protein in a canned dog food vs. 27% protein in a dry dog food) reflects the fact that there is more water in the canned food.

Pet Food Additives

Some other substances that might be found in pet foods, which are not required nutrients, are described below:

Chondroprotective agents are used by the body to make cartilage and joint tissues. Although, use of chondroprotective agents may be indicated for
selected clinical conditions, widespread inclusion in the diets of healthy populations may not be warranted at this time.

Antioxidants work to prevent oxidative damage to nutrients and other compounds in the body and inhibit or quench the formation of free radicals. At this time, data are lacking to make specific recommendations beyond those for the essential vitamins and minerals that are components of antioxidants.

Herbs and botanicals are used in pet foods either to provide flavor or, more often, to have a medicinal effect on the body. This is especially true in the case of extracts, where the classical nutritive components of the plant may be separated from the extract in the process. Because the intended functions are more pharmacologic versus nutritional in nature, discussion of potential benefit is beyond the scope of this publication.

Flavors and extracts derived from animal tissues such as poultry or fish are considered “natural” flavors. A wide variety of flavors can be derived from other animal and plant materials, including dairy products, eggs, herbs and spices. Acceptable processing methods include roasting, extraction, and fermentation. Except for artificial smoke and bacon flavors, synthetic substances are rarely used in most dog and cat foods.

Colors are synthetic compounds used to replace or accentuate the inherent color of the food. Only certified colors approved for use in human foods are allowed in pet foods. Iron oxide is a synthetic but noncertified color that can be used at levels not to exceed 0.25% of the pet food product to give dog and cat food a red, meaty appearance.

Titanium dioxide is another common color additive in human and pet foods because it can induce a “brightness” in foods by complementing other color additives. Its use is limited to 1% of the food by weight.


Vitamins are organic compounds that take part in a wide range of metabolic activities. Dogs require vitamins in their food, albeit at low concentrations. First noticed in dogs some 75 years ago, vitamin deficiencies can cause a variety of health problems.

Clinical signs of vitamin A deficiency, one of the first deficiencies studied in dogs, include motor and vision impairment, skin lesions, respiratory ailments,
and increased susceptibility to infections.

Dogs fed diets lacking vitamin E show signs of skeletal muscle breakdown, reproductive failure and retinal degeneration.

Thiamin deficiency can lead to brain lesions and other neurological abnormalities if the deprivation is sudden and to heart damage and death if it is chronic.

Some vitamins, such as vitamin D, are not only essential in small doses, but also toxic in excess amounts.

Daily Recommended Allowances for Vitamins
Functions Recommended Allowance Signs of Deficiency / Excess
Vitamin A Vision; growth; immune function; fetal development; cellular differentiation; transmembrane protein transfer 379 μg Anorexia; body weight loss; ataxia; conjunctivitis; corneal disorders; skin lesions; respiratory ailments; increased susceptibility to infection; imbalance in bone remodeling processes; artery and vein degeneration; dehydration; central nervous system depression; joint pain
Vitamin D Maintenance of mineral status; phosphorous balance 3.4 μg Rickets; lethargy; loss of muscle tone; bone swelling and bending; anorexia; weakness; diarrhea; vomiting; calcification of soft tissue; excessive mineralization of long bones; dehydration; dry and brittle hair; muscle atrophy
Vitamin E Defense against oxidative damage 8 mg Degeneration of skeletal muscle; reproductive failure; retinal degeneration

Image credit: Wikimedia.



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